Pinpoint Test B: The Wipers Are Inoperative - Rear Window
Wipers and Washers
Pinpoint Test B: The Wipers are Inoperative - Rear Window
Refer to Wiring Diagram Set 81, Wipers and Washers for schematic and connector information. Diagrams By Number
Normal Operation
Power is supplied from the Central Junction Box (CJB) to the Body Control Module (BCM) for the rear window wiper system when the ignition is in the ON position. The BCM supplies a signal voltage(s) to the wiper/washer switch for the CONTINUOUS and INTERMITTENT wiper functions. Both functions share a dedicated signal (sense) line. The wiper/washer switch physically grounds the signal voltage(s) when a function is selected. The BCM then reacts to the grounded signal voltage(s) and its integral electronics make a decision on which wiper system function to carry out (depending on the windshield wiper setting). Ground is supplied to the rear window wiper motor through its own dedicated circuit.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Wiper/washer switch
- Rear window wiper motor
- BCM
PINPOINT TEST B: THE WIPERS ARE INOPERATIVE - REAR WINDOW
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B1 CHECK FOR BCM DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self-Test - BCM.
- Are any BCM DTCs present?
Yes
REFER to the Body Control Module (BCM) DTC Chart for further diagnosis. [1][2]Diagnostic Trouble Code Descriptions
No
GO to B2.
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B2 CHECK THE BCM PID REAR WIPER INPUT SWITCH STATUS (R_WP-SW)
- Enter the following diagnostic mode on the scan tool: DataLogger - BCM.
- Monitor the BCM PID R_WP-SW while operating the wiper/washer switch in the rear wiper mode.
- Does the status of the PID match the wiper/washer switch setting?
Yes
GO to B5.
No
GO to B3.
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B3 CHECK THE WIPER/WASHER SWITCH
- Ignition OFF.
- Disconnect: Wiper/Washer Switch C2081.
- Carry out the wiper/washer switch component test.
Refer to Windshield Washer Switch or Wiper Switch for component testing.
- Does the wiper/washer switch pass the component test?
Yes
GO to B4.
No
INSTALL a new wiper/washer switch. REFER to Steering Column Switches Steering Column Multifunction Switch. TEST the system for normal operation.
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B4 CHECK THE WIPER GROUND CIRCUIT FROM THE BCM AND THE REAR WIPER INTERVAL CIRCUIT
- Disconnect: BCM C2280E.
- Disconnect: BCM C2280F.
- Measure the resistance between wiper/washer switch C2081-4, circuit CRW20 (GY/YE), harness side and BCM C2280E-5, circuit CRW20 (GY/YE), harness side and between wiper/washer switch C2081-5, circuit CRW17 (GN/VT), harness side and BCM C2280F-16, circuit CRW17 (GN/VT), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to B5.
No
REPAIR the affected circuit. TEST the system for normal operation.
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B5 CHECK THE REAR WINDOW WIPER MOTOR GROUND FOR AN OPEN OR HIGH RESISTANCE
- Ignition OFF.
- Disconnect: Rear Window Wiper Motor C4218.
- Measure the resistance between rear window wiper motor C4218-3, circuit GD143 (BK/VT), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to B6.
No
REPAIR the circuit. TEST the system for normal operation.
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B6 CHECK THE BCM VOLTAGE
- Disconnect: BCM C2280B.
- Ignition ON.
- Measure the voltage between BCM C2280B-15, circuit CBP13 (GY/BN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to B7.
No
VERIFY Central Junction Box (CJB) fuse 13 (15A) is OK. If OK, REPAIR circuit CBP13 (GY/BN) for an open or high resistance. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the short to ground. Diagrams By Number
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B7 CHECK REAR WINDOW WIPER MOTOR SUPPLY AND RELAY OUTPUT CIRCUITS FOR AN OPEN OR HIGH RESISTANCE
- Ignition OFF.
- Disconnect: BCM C2280C.
- Measure the resistance between rear window wiper motor C4218-1, circuit CRW02 (GY/BU), harness side and BCM C2280C-11, circuit CRW02 (GY/BU), harness side and between rear window wiper motor C4218-2, circuit CRW05 (BU), harness side and BCM C2280C-9, circuit CRW05 (BU), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to B8.
No
REPAIR the affected circuit. TEST the system for normal operation.
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B8 CHECK FOR VOLTAGE TO THE REAR WINDOW WIPER MOTOR USING THE BCM PID REAR WIPER RELAY (WPR_RLY_REAR)
- Connect: BCM C2280B.
- Connect: BCM C2280C.
- Connect: BCM C2280E.
- Connect: BCM C2280F.
- Connect: Wiper/Washer Switch C2081.
- Ignition ON.
- Command the BCM PID WPR_RLY_REAR on.
- Measure the voltage between rear window wiper motor C4218-1, circuit CRW02 (GY/BU), harness side and ground and between rear window wiper motor C4218-2, circuit CRW05 (BU), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to B9.
No
GO to B10.
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B9 CHECK FOR CORRECT WIPER MOTOR OPERATION
- Ignition OFF.
- Inspect rear window wiper motor C4218 for the following conditions:
- corrosion
- damaged or pushed out pins
- Connect the rear window wiper motor C4218 and make sure it seats correctly.
- Operate the system and verify if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new rear window wiper motor. REFER to Wiper Motor - Rear Window Wiper Motor - Rear Window. TEST the system for normal operation.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
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B10 CHECK FOR CORRECT BCM OPERATION
- Ignition OFF.
- Inspect the BCM connectors for the following conditions:
- corrosion
- damaged or pushed out pins
- Connect the BCM connectors and make sure they seat correctly.
- Connect: Rear Window Wiper Motor C4218.
- Operate the system and verify if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new BCM. REFER to Multifunction Electronic Modules Body Control Module (BCM). TEST the system for normal operation.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
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